161265825 has 144 divisors (see below), whose sum is σ = 369083520. Its totient is φ = 65525760.

The previous prime is 161265773. The next prime is 161265889. The reversal of 161265825 is 528562161.

It is not a de Polignac number, because 161265825 - 2¹⁰ = 161264801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161265825.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 508567 + ... + 508883.

It is an arithmetic number, because the mean of its divisors is an integer number (2563080).

Almost surely, 2^161265825 is an apocalyptic number.

161265825 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161265825 is an abundant number, since it is smaller than the sum of its proper divisors (207817695).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161265825 is a wasteful number, since it uses less digits than its factorization.

161265825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376 (or 368 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 161265825 is about 12699.0481926796. The cubic root of 161265825 is about 544.3114217181.

The spelling of 161265825 in words is "one hundred sixty-one million, two hundred sixty-five thousand, eight hundred twenty-five".